Yeah, I don't quite know the details of how it works. Just that it does

  $ file some.*
  some.jpg: JPEG image data, JFIF standard 1.02, aspect ratio, density 1x1, segment length 16, baseline, precision 8, 64x736, components 1
  some.zip: Zip archive data, at least v1.0 to extract
  $ cat some.* > new.jpg
  $ file new.jpg
  new.jpg: JPEG image data, JFIF standard 1.02, aspect ratio, density 1x1, segment   length 16, baseline, precision 8, 64x736, components 1
  $ unzip -l new.jpg
  Archive:  new.jpg
  warning [new.jpg]:  1557 extra bytes at beginning or within zipfile
    (attempting to process anyway)
    Length      Date    Time    Name
  ---------  ---------- -----   ----
          0  2022-04-28 21:53   stuff/
          5  2022-04-28 21:53   stuff/a
          5  2022-04-28 21:53   stuff/c
          5  2022-04-28 21:53   stuff/b
  ---------                     -------
         15                     4 files
  $